Art of annealing



UNITED STATES PAUL A. MEEHAN, OF NEW CASTLE, PENNSYLVANIA,

DRESSLER TUNNEL KILNS, INC., OF NEW YORK, N. Y.,

PATENT OFFICE.

ASSIGNOR- TO AMERICAN A CORPORATION OF NEW Patented Aug. 23, 1921.

To all whom it may concern:

Be it known that I, PAUL A. MEEHAN, a

citizen of the United States, and a resident of New Castle, in thecounty of Lawrence and State of Pennsylvania, have invented certain newand useful Improvements in the Art of Annealing, of which the followingis a specification.

The object of the present invention is to overcome a difiiculty whicharises in the ordinary practice of annealing metallic articles whichhave been previously pickled in an acid bath. In annealing such articlesit is practically difiicult to remove all acid from the articles beforethey are put into annealing boxes, or on other supports and are movedinto the annealing kiln orfurnace. In consequence the annealing boxes orother supports for the articles, if made of metal as is ordinarily thecase, areattacked by the acid fumes and are subjected to consequentrapid deterioration. If the kiln or annealing furnace contains metallicparts, these are also attacked by the acid fumes. This is especiallytrue when the annealing furnace is of the continuous tunnel type andcomprises metallic cooling pipes in the cooling zone of the kiln.

I have discovered that this difliculty may be effectively andinexpensively overcome by the simple expedient of coating, from time totime, the boxes or other supports for the articles to be annealed withan acid neutralizing material, and in practice I coat the Applicationfiled April 20, 1920. Serial No. 375,271.

boxes or other supportswith whitewash. When the acid from the picklingbath is sulfuric acid I remove the calcium sulfate formed by thereaction betwen the lime in the whitewash and the acid. If some otheracld is used the corresponding calcium salt must be similarly removed.In practice 1 may remove the salt thus formed at the .end

of each annealing operation, and then recoat I the boxes or othersupports, but in some cases the boxesor other supports may be used intwo or three annealing operations for each cleaning and coatingoperation, and thorough cleaning at any time is ordinarily notnecessary.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. The improvement in the art of annealing acid pickled articles held bymetallic supports which consists in neutralizing acid retained on sucharticles by acid neutralizing material supplied in the form of a coatingto said supports from time to time.

2. The improvement in the art of annealing acid pickled articles inmetallic boxes which consists in neutralizing acid retained on sucharticles by whitewash supplied to the boxes from time to time.

Signed at New Castle, in the county of Lawrence and State ofPennsylvania, this 10th day of April, A. D. 1920.

' PAUL A. MEEHAN;

